1. Field of the Invention
The present invention relates to an air conditioner that is equipped with an operating device having an analog operating member and sets a set temperature of an indoor unit in accordance with an operation of the analog operating member, a method of controlling the air conditioner, a temperature setting device for the air conditioner, and a method of controlling the temperature setting device.
2. Description of the Related Art
There is known an air conditioner for air-conditioning each guest room of a hotel or the like that is equipped with an operating device having a temperature adjusting dial, detects an analog value (for example, a voltage value) continuously-variable in accordance with an operation of the temperature adjusting dial and sets the set temperature of a room to be air-conditioned on the basis of the thus-detected analog value (JP-A-7-305882, for example). In this type of air conditioner, the setting of the set temperature is carried out by each of plural indoor units to which respective operating devices are connected, and required power of each indoor unit determined on the basis of the set temperature and the room temperature is transmitted to an outdoor unit through data communication, and the outdoor unit drives a compressor with the driving power corresponding to the required power from each indoor unit.
In the construction of the air conditioner described above, the relationship between an analog value indicating the rotational position of the temperature adjusting dial and the set temperature set on the basis of the analog value is fixed to one-to-one correspondence relationship, and when the operable temperature range of each indoor unit is varied in accordance with the operation mode, for example when it is set to the range from 18° C. to 30° C. under cooling operation and also set to the range from 16° C. to 26° C. under heating operation, the variable range of the set temperature corresponding to the variable range of the analog value is set to the range from 16° to 30° C., that is, the range from the minimum temperature to the maximum temperature of all the operation modes.
However, if the variable range of the set temperature is set to the range from the minimum temperature to the maximum temperature of all the operation modes, an unchangeable range in which the set temperature is not changeable because the set temperature is out of the set temperature range to which the indoor unit is adaptable even when the temperature adjusting dial is operated occurs every operation mode. For example, when the operable temperature range under cooling operation is from 18° C. to 30° C., the set temperature is fixed to 18° and unchangeable from this temperature even when the temperature adjusting dial is operated to the position corresponding to the temperature from 16° C. to 18° C. Furthermore, when the operable temperature range under heating operation is from 16° C. to 26° C., the set temperature is fixed to 26° C. and unchangeable from this temperature even when the temperature adjusting dial is operated to the position corresponding to the temperature from 26° C. to 30° C.
As described above, when the unchangeable range in which the set temperature is unchangeable occurs, an operation range which can be allocated every set temperature is narrowed by the amount corresponding to the unchangeable range, and thus the frequency at which the temperature adjusting dial is located at a set temperature switching point is increased. In this case, when the temperature adjusting dial is located at a set temperature switching point, the set temperature concerned is repetitively changed between the temperatures before and after the switching point irrespective of the non-operation of the temperature adjusting dial, and thus the transmission processing of the required power is frequently executed in accordance with the change of the set temperature, so that the communication line between the indoor unit and the outdoor unit is congested.
Furthermore, the operable temperature range of the indoor unit is also varied in accordance with the type of the indoor unit. When the set temperatures satisfying the operable temperature ranges of these types are allocated within the operation range of the temperature adjusting dial in order to adapt to all the types as described above, there occurs an unchangeable range in which the set temperature is unchangeable even when the temperature adjusting dial is operated, resulting in occurrence of the congestion of the communication line.